The Theory

Jean Piaget was a Swiss psychologist who revolutionized the realm of developmental psychology. The notion that children thought differently from adults intrigued Piaget – this in turn catalyzed a series of studies that lead him to his theory of cognitive development. The essence of Piaget’s theory is that children are “active scientists” and that a child’s cognitive development passes through different stages. The stage theory also branches out into the theory of egocentrism and conservation.

Children as “Active Scientists”

Piaget used the constructionist approach to explain the idea of “active scientists” wherein children are not a blank slate, but instead driven by biological maturation. As the brain develops physically, cognitive capacity does as well. He believed that children construct knowledge as they interact with the world around them. This in turn creates a personal mental representation for a child, otherwise known as “schemas”. These schemas are what dictate how someone interacts with and interprets the world around them, beginning with innate schema such as sucking and grasping.  The crux of schema lies in equilibration, where a child desires to understand the world around them. If this is not the case, disequilibrium occurs and the  schemas develops and is modified through the processes of assimilation and accommodation. Assimilation occurs when new information is added to a child’s cognitive schema, such as when they learn new information in the classroom. Accommodation occurs when existing schemas need to be modified because they do not match the new experience. For example, a child may have a cognitive schema for the shape of a square. However, when presented with the shape of a triangle, the child will need to accommodate his or her schema to exclude the shape of a rectangle from the shape of a square, and create new schema for the rectangle. This sheds light on how children learn in the classroom: actively, and always processing information.


The Stage Theory

Piaget believed that a child’s intelligence progressed through a series of cognitive stages. All stages were unique from one another, yet it was a universal theory where the content and sequence were the same for all humans. In addition, a child cannot learn at a higher level or stage without passing through the initial lower levels.

The stages are as follows:

Stage Theory

Egocentrism – When a child has difficult seeing things from the perspective of somebody else

Conservation – When a child does not understand that objects remain constant even if the visible appearance changes (E.g. hidden under a blanket)

Piaget's Theory



  • Piaget has influenced the realm of developmental psychology greatly, and changed how people have viewed a child’s cognitive development. This has also generated research which has increased the knowledge in this area of psychology and lead to other theories.
  • Supported by many studies
  • Support from cross-cultural studies
  • Piaget’s ideas have had practical use in classroom settings.


  • The notion of age-restricted stages has been questioned by other developmental psychologists such as Vygotsky who argue that development is continuous.
  • Piaget fails to address social factors in his theory, as Vygotsky argues that children begin sociocentric and then progress to egocentric. In a classroom setting, this would be seen with group work between children as Vygotsky’s theory claims that knowledge is transferred through collaborative learning.
  • The method of Piaget’s studies has limitations as the sample size was small and he sometimes used his own children as participants. Because he was the only researcher in his studies, there may be bias in his own interpretations of his observations.
  • The language used in Piaget’s conservation tasks have been criticized as being too advanced for the children, thus they were unable to understand the question and could not properly answer the conservation task questions.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s